During explosive forming, a work piece is arranged in a die and deformed by igniting an explosive, for example, a gas mixture, in the die. The explosive is generally introduced to the die, and also ignited here. Two problems are then posed. On the one hand, the die or ignition mechanism must be suitable for initiating the explosion in targeted fashion and withstanding the high loads that occur during the explosion and, on the other hand, good forming results in the shortest possible setup time must be achieved repeatedly.
In a method known from EP 0 830 907 for forming of hollow elements, like cans, a hollow element is inserted into a die and the upper opening of the hollow element closed with a plug. An explosive gas is introduced to the cavity via a line in the plug, which is then ignited via a spark plug arranged in the plug.
In a method described in U.S. Pat. No. 3,342,048, a work piece to be deformed is also arranged in the die and filled with an explosive gas mixture. Ignition occurs here by means of mercury fulminate and a heating wire or filament. Both methods are particularly suited for single part production and have not been able to gain acceptance in practice for mass production.